[Decussations in the human muscular system]. / Perekresty v myshechnoi sisteme cheloveka.

There are decussations in all groups of muscles: mimic, m. masseter, in muscles of the trunk and extremities. The classification presented divides all the decussations into 3 groups: 1 -- decussations of the muscles situated in the neighbouring layers of the same topographic area; 2 -- decussations of muscles-synergists a) at the place of their origin, b) along their course, c) at the place of their attachment; 3 -- decussation of fibres within the limits of one muscle, as well as decussation of tendons in one muscle. If there is a decussation in a definite group of muscles, it is possible to suggest that there is a decussation in the antagonistic group of muscles or in the muscles situating at the opposite side of the trunk. Conformity of decussations in the antagonistic groups of muscles can surve as a morphological demonstration of their functional unity. Basing on the laws of biomechanics and constructive engineering, an attempt is made to explain the biological expedience of the oblique and crossed course of the muscles. In the orthopedic operative surgery in order to strengthen the joints, artificial muscle decussations are used, thus natural models of the crossed course of the muscles become more firm. Owing to the regularities stated, it is possible to elaborate new reconstructive operations in various parts of the human body.

Functional anatomy of physiologic atresia in human and mammal embryogenesis.

1. Physiological atresias represent temporal functionate structures that appear and disappear in various organs at different stages in embryonic development. 2. The phenomen of physiological atresia has its morphological and time characteristics in different organs and systems. The universal occurrence of the epithelial adhesion observed in the viscera and natural apertures in the body have functional significance for the embryo in its adaptation to the development in the amniotic medium. 3. Deviations in recanalization of fetal occlusions result in the appearance of congenital atresia and other defects in the development. This is grounded by some indirect evidences. 4. Detailed a knowledge of embryogenesis has clinical importance in explaining the observed congenital anomaly and for their diagnosis and correction.

[Development of the nasal cavity and formation of the nostrils in human embryogenesis]. / Razvitie polosti nosa i obrazovanie narushnykh nosovykh otverstii v embriogeneze cheloveka.

The development of nasal cavity was traced in human embryos. The identity in the primitive formation of the mouth cavity and that of the nasal cavity is stated. During embryogenesis, the primitive nasal cavities are demonstrated to change their position concerning the mouth cavity. Epithelial "cluster" formation in the area of the nostrils is examined: it appears in embryos of 16-19 mm long, is mostly prominent in embryos of 50-55 mm long, is absent in fetuses of 5.5 months old. By comparing the terms and dynamics in the development of epithelial adhesion in the larynx an the nostrils, the importance of these temporal structures for protecting the respiratory tract of the embryo from amniotic fluid is demonstrated.